In optical devices, such as photographing devices, for example, a camera, a camcorder, or the like, a distance measuring equipment, a magnifying glass of various kinds of telescopes, and the like, a microscope which observes micro objects, and the like, a shape, a position, a distance, a size, and the like of an optically observed object are transferred to a user's eye through an optical path of the optical devices. In this specification, the optical path may be defined as a path from a lens of the optical device to a check window, such as a view finder.
The optical path may be provided with screen parts which may display optical information of an object, such as a device set-up value of the optical device and a focus or a position such as a distance of an optically observed object.
For example, a camera which is a representative example of the optical device includes a finder screen configured to display a focus of a subject, which is an optically observed object, within an optical path between a lens and a view finder and a set-up display screen configured to display device set-up values of the camera.
Hereinafter, a structure that screen parts are installed in a single-lens reflex camera (hereinafter, referred to as a “SLR camera”) which is a kind of camera will be described in detail.
As illustrated in FIG. 1, a general SLR camera vertically reverses an image of a subject input though a lens 103 through a reflecting mirror 110 inside a camera body 101, passes the vertically reversed image through a finder screen 120 and a set-up display screen 130 which are screen parts, reverses the vertically reversed image to a normal position again while passing through a pentaprism 140, and then transfers the normally reversed image to a photographer's eye through a view finder 150.
In this configuration, the finder screen 120, which focuses a subject, has a structure in which a single focus pattern or a plurality of focus patterns (not illustrated) are printed on a light-transmissive plate.
The finder screen 120 is electrically connected to a shutter button (not illustrated) and a controller (not illustrated) of the camera body 101 so as to be able to transmit a control signal to each other, and light-emits the corresponding focus pattern (not illustrated) toward a subject by a control of the controller (not illustrated) during a process of allowing a photographer to press the shutter button (not illustrated) so as to enable the photographer to confirm a focus.
Meanwhile, the set-up display screen 130 displays device set-up information to enable a photographer to confirm device set-up values, such as exposure and photographing sensitivity, through the view finder 150. The set-up display screen 130 has a structure in which an information display pattern (not illustrated) on which various types of photographing information or photographing set-up values are displayed is printed on the light-transmissive plate.
The set-up display screen 130 is electrically connected to the shutter button (not illustrated), an aperture dial (not illustrated), an exposure time control dial (not illustrated), a sensitivity control button (not illustrated), a controller (not illustrated), and the like, to be able to transmit control signals to each other.
Therefore, the corresponding photographing information, the photographing set-up values, or the like is light-emitted on the information display pattern (not illustrated) by the control of the controller (not illustrated) during a process of allowing a photographer to press the shutter button (not illustrated) halfway or operate the aperture dial (not illustrated), the exposure time control dial (not illustrated), the sensitivity control button (not illustrated), and the like, such that the photographer may confirm the corresponding photographing information, the photographing set-up values, or the like.
However, since the screen parts which are installed in the optical device, such as a conventional SLR camera are provided in plural, such as the finder screen and the set-up display screen, the number of parts is increased, such that a mechanical design inside the optical device may be complicated and a mechanical restriction and parts cost may be increased.
Further, a volume of the finder screen and the set-up display screen which are installed in the optical device, such as the conventional SLR camera, must be thick enough to form the focus pattern and the information display pattern which are a light-emitting pattern. Therefore, there is a problem in that the optical device may be structurally and mechanically restricted at the time of installing the screen parts therein.
Further, in order to avoid a mutual interference of the light-emitting pattern (for example, the focus pattern and the information display pattern as described above) between the respective screen parts, there is a problem in that a display region of the light-emitting pattern is restricted.
Further, each of the screen parts is to form the light-emitting patterns on the light-transmissive plate. In this case, since the light-emitting pattern is positioned on the optical path, there is a problem in that visibility of an optically observed object may be deteriorated.
Meanwhile, the finder screen and the set-up display screen which are installed in the optical device, such as the conventional SLR camera, may not implement various colors due to characteristics of a light-emitting device. As a result, an information display depending on emission of light is merely transferred to a user and thus the user does not carefully recognize the corresponding information, and the like, such that usability of the optical device may be reduced.